Upper Oligocene evaporites in basin fill of Sevier Desert region, western Utah

Journal Article · Sun Feb 01 04:00:00 EST 1981 · Am. Assoc. Pet. Geol. Bull.; (United States)

OSTI ID:6499570

Lindsey, D A ^[1]; Glanzman, R K; Naeser, C W; Nichols, D J

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1. Geological Survey, Denver, CO

The basin fill beneath the Sevier Desert of western Utah contains evaporites of late Oligocene age that were deposited in a broad closed basin. All of the basin fill penetrated by the Gulf Oil 1 Gronning (2458 m TD), one of only three deep holes in the basin, contains abundant volcanic detritus and its alteration products of Cenozoic age, when volcanism was intense in western Utah. Fission-track dating of tuffaceous sandstone, interbedded with evaporite minerals and representative of sandstone in the lower formations penetrated, yields ages of 26 to 28 m.y.; concordance of ages indicates no thermal resetting. Fossil pollen from mudstone in the evaporite-bearing strata includes forms no older than late Oligocene, in good agreement with the fission-track ages. Thus the age of the evaporites, and of all the basin fill penetrated by drilling, is late Oligocene and younger; previous work had assigned them ages ranging from Triassic to Eocene. Evaporite-bearing rocks were deposited during late Oligocene time in a broad closed basin under arid or semiarid conditions much like those of the Great Basin today. Anhydrite is present throughout approximately 900 m of volcaniclastic rocks in the lower part of the section cut by the Gulf hole, and more than 1500 m of anhydrite and halite is present in possibly equivalent strata in the nearby Argonaut dry hole. Fossil pollen from anhydrite-bearing rocks in the Gulf hole are indicative of an arid to semiarid flora, including plants similar to Mormon tea and possibly saltbush or buffalo berry. Evaporite minerals formed in the basin during dry periods; tuff was erupted from nearby volcanic centers, reworked by water, and deposited in the basin.

• OSTI ID: 6499570
• Journal Information: Am. Assoc. Pet. Geol. Bull.; (United States), Journal Name: Am. Assoc. Pet. Geol. Bull.; (United States) Vol. 65-2; ISSN AAPGB
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580100* -- Geology & Hydrology-- (-1989)
AGE ESTIMATION
ALKALINE EARTH METAL COMPOUNDS
ANHYDRITE
CALCIUM COMPOUNDS
CALCIUM SULFATES
CENOZOIC ERA
EVAPORITES
FOSSILS
GAMETES
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGY
GERM CELLS
MINERALS
NORTH AMERICA
OXYGEN COMPOUNDS
POLLEN
ROCKS
ROCKY MOUNTAIN REGION
SALT DEPOSITS
SANDSTONES
SEDIMENTARY ROCKS
STRATIGRAPHY
SULFATES
SULFUR COMPOUNDS
TERTIARY PERIOD
USA
UTAH
WELLS